Journal of Gems & Gemmology

2023, 25(1): .

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Study on Colour Characteristics and Quantitative Classification of Nanhong Agate Based on HSB Colour Space

WANG Haotian, HUANG Huimin, YANG Lingyue, YANG Mingxing, HONG Hanlie, WANG Chaowen

2023, 25(1): 1-13. doi: 10.15964/j.cnki.027jgg.2023.01.001

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In recent years, the price of the Nanhong agate has been rising in jewelry market. As one of the most important factors affecting the quality evaluation of the Nanhong agate, its colour is closely related to the market price. However, the national grading standard of the Nanhong agate has not yet introduced. In order to make the evaluation process of the Nanhong agate colour more objective, scientific and standardized, this paper focuses on the colour characteristics and quantitative classification of the Nanhong agate. The colour images of the samples were obtained by light boxes and cameras. Based on HSB colour space, the colour of the Nanhong agate were standardized and quantified. Origin and SPSS softwares were used to statistically analyze the hue, saturation and brightness (HSB) parameters of the obtained colour data. The results showed that at the 95 % confidence level, the hue (H) of the red Nanhong agate was mainly distributed in a range between[3.20°, 17.52°]. The saturation (S) and brightness (B) were mainly within [63.82%, 92.69%] and [42.97%, 75.37%], respectively. The statistical results were consistent with the visual observed colour characteristics of the Nanhong agate. Combined the characteristics of visual observed colour with the TwoStep cluster analysis, this paper recommends to classify the colour of the red Nanhong agate as follow. The H is divided into three categories, including red (R), orange red (oR), red orange (rO). The S is divided into three levels: S₁, S₂ and S₃. The B is also divided into three levels: B₁, B₂, and B₃. For the saturation (S) in different colour varieties, the "Shizihong""Shuihong" and "Jinhong" (different kinds of red) have greater S than other varieties; the "Binghong" and "Meiguihong" are medium, and the "Bingfen" is the lowest. For brighthess (B), the values of "Bingju" and "Shuihong" are the brightest; the "Shizihong" "Binghong" and "Bingfen" are medium, and the "Jinhong" and "Meiguihong" are the lowest. The colour names of the Nanhong agate in the market are scientifically distinguished and the accurate range of each variety in HSB space is recommended based on the colour distribution characteristics above and the colour grading results.

Gemmological and Mineralogical Characteristics of Pink Hydrogrossular

ZHENG Yalong, CHEN Meihua, SUN Ruizhen, LIU Jia, WANG Chengbo

2023, 25(1): 14-20. doi: 10.15964/j.cnki.027jgg.2023.01.002

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The pink hydrogrossular samples were tested by conventional gemmological tests, X-ray powder diffraction spectrometer(XRD), Fourier infrared spectroscopy(FTIR), polarizing microscope, microscopic UV-Vis spectrometer and energy dispersive X-ray fluorescence spectrometer (EDXRF), to analyze their chemical compositions, mineral components, microstructures and possible colour origins. The results of X-ray powder diffraction test showed that the pink hydrogrossular samples are composed of hydrogrossular and vesuvianite, and the results of polarizing microscopic test showed that the main mineral hydrogrossular is in granular shape and showing different concentrations of pink by microamplification. A small amount of vesuvianite is in fibrous shape scattered in the inside of the pink hydrogrossular with the colour of brown green under the microscopic observation.According to the results of polarized light microscope, microscopic UV-Vis spectroscopy and EDXRF, the pink colour of the hydrogrossular samples is related to trace elements Fe and Mn, and Mn is the main colour cause.

Fluorescence Characteristic of Fluorite from Namibia

LI Yuanjing, Shen Andy Hsitien

2023, 25(1): 21-27. doi: 10.15964/j.cnki.027jgg.2023.01.003

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The fluorite produced in Namibia has special colour zones and prismatic inclusions, and its purple cubic ring structure shows strong blue-purple fluorescence under long-wave UV light (365 nm). In order to study the fluorescence characteristics of fluorite from Namibia, the microscopic observation and photography, inductively coupled plasma mass spectrometer (ICP-MS), laser Raman spectrometer, and fluorescence spectrometer were used. ICP-MS testing results of different colour parts of the fluorite sample showed that the concentration of rare earth elements in the purple part was higher than that in the yellow part. In terms of element types, the concentration of rare earth element Ce and Y was higher, and the purple part concentrates twice as much Ce as the yellow part.Raman spectra showed that besides the characteristic peak of fluorite, there are several unstable spectral peaks indicating the rare earth element Er. Combined the photoluminescence spectra with 3D fluorescence spectra, the results showed the luminescence center of Ce³⁺ with very high intensity existed within the excitation wavelength and emission wavelength (Ex/Em) range 310 nm/320 nm and 310 nm/340 nm. According to the testing results of spectra and trace elements, the characteristic blue-violet fluorescence of the fluorite sample from Namibia is produced by Ce.

Synchrotron Radiation μ-XRF Imaging Reveals Oscillatory Zoning of Freshwater Pearls

GAO Jing, ZHANG Jinli, Yen Chien-Kuo

2023, 25(1): 28-35. doi: 10.15964/j.cnki.027jgg.2023.01.004

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Pearls and shells are common biominerals characterized with a highly organized laminar structure that is constructed by inorganic aragonite platelets alternating with organic material films. Formed in the bodies of mollusks, the uptake of trace elements into pearls and shells is under both biological control and environmental control. Thus, the spatial and temporal resolution of the trace element distributions could reflect the life activities of the mother mollusks and the chemistry of the environments. However, elemental maps in pearls and shells have not received due attention from previous studies. In this study, the elemental profile in cultivated pearls is carefully investigated using synchrotron radiation μ-X-ray fluorescence imaging. A variety of trace elements such as Ti, V, Mn, Fe, Ni, Cu, Sr and Ba has been detected. Most elements are distributed evenly in these pearls, with exceptions of Mn, Fe and Ba that show oscillatory zoning in freshwater pearls, coupled with the pearl growth pattern. Mn zoning is ubiquitous in all the freshwater pearls, with different numbers, width, positions, and Mn concentrations, etc. in individual. In some pearls, the Mn zoning are cooperative with the Fe zoning. It is suggested that the oscillatory zoning in freshwater pearls is a dissipative structure, and its formation results from metabolic rate changes of the mother mollusks after pearl-mantle-inserting operation. The presence of the Mn oscillatory zoning is expected to be a key character of freshwater pearls, as no such zoning is found in seawater pearls. Seawater pearls are featured with extremely low Mn concentrations. It is thus, speculated that marine Pinctada martensii have different requirements for trace elements in the course of biomineralization in comparison with freshwater Hyriopsis cumingii, and could maintain relatively stable metabolism during pearl growth. In view that pearls and shells show highly similar crystal chemistry, it is reasonable to believe that the elemental profile in shells may also be affected by the mother mollusks' activities. So the geochemical signature of shells should be treated with caution to reconstruct environments.

Preliminary Study on Infrared Holographic Imaging of Amber from the Baltic Sea

YAO Yuan, HUANG Haochong, CHEN Xingyun, GUO Yu, YANG Biao, ZHENG Zhiyuan

2023, 25(1): 36-44. doi: 10.15964/j.cnki.027jgg.2023.01.005

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In order to explore the relationship between the optical properties and composition of amber and further establish the effective infrared parameters of amber authenticity identification, infrared holographic method was used to image and detect 5 amber samples from the Baltic Sea, and the imaging effect was analyzed by microscope and X-ray fluorescence spectroscopy. According to the principle of infrared holography, the parallel light vertical shooting optical path is built by using the near-infrared laser light source, and the hologram of different positions of the amber sample is obtained and reconstructed, and the image shows that the imaging effect of the amber sample at different locations has differences. For the difference in the infrared band transmittance of the amber sample at different locations, X-ray fluorescence spectroscopy was performed to obtain the elemental content at different locations. Combined with the infrared holographic imaging results, the analysis showed that S element and Si element were the main elements affecting the infrared transmittance of amber, and the content of S element of the testing points with inclusion was lower than that without inclucion, and the content of Si element of the testing point with inclusion was higher than that without inclusion. It was concluded that the Si element was conducive to infrared transmission, and the S element was not conducive to infrared transmission. Studies have shown that the optical path of vertical parallel light shooting is suitable for amber infrared holographic imaging, which is a new optical tool for amber characterization.

Identification Method of Glue-Filled Aquamarine

CAO Nan, CHEN Tao, ZHENG Jinyu, CHEN Xin, ZHUANG Yue, WANG Ziwei

2023, 25(1): 45-51. doi: 10.15964/j.cnki.027jgg.2023.01.006

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As aquamarine becomes more and more popular with consumers, a large number of aquamarines that have been filled with glue began to appear in the market. This treatment improves the durability and appearance of aquamarine to a certain extent, but it still needs to be marked as "treatment" during trade. This article uses conventional gemmological testing methods, Fourier transform infrared spectrometer, and laser Raman spectrometer to analyze and study the identification method of glue-filled aquamarine in depth. The refractive index of the glue-filled aquamarine is 1.577 to 1.583, which is in the normal range, but the relative density is low(2.55-2.70). Microscopic magnification inspection can often see the residue of the filling of the surface, and there is a difference in luster of the crack between the filler and the main body, and the bubbles produces by glue injection and blue-purple flash effect can be seen in the depth of the fracture. Under ultraviolet fluorescent lamps, the filler mostly emits a distinct blue-white fluorescence along the fissure or pit. The infrared spectrometer shows the telescopic vibration band of methylene (—CH₂—) and methyl (—CH₃—) at 2 872, 2 930, 2 962 cm^-1 and methyl (—CH₃—) and the absorption peak caused by the benzene ring at 3 032, 3 058 cm^-1 and weak absorption peak at 4 065 cm^-1. Raman spectra showed that the filler mainly appeared two sets of Raman displacement combination at 1 113, 1 186, 1 608 cm^-1 and 2 870, 2 924, 3 066 cm^-1, and Raman spectrum peaks at the 2 924 cm^-1 and 2 870 cm^-1are attributed to the stretching vibration of methyl (—CH3—) and methylene (—CH2—) and the rest of the Raman shift are due to the benzene ring. Both blue flash and ultraviolet fluorescence can be used as the most intuitive and convenient detection methods for glue-filled aquamarine, and infrared spectroscopy and Raman spectroscopy testing technology can provide a strong scientific basis for identifying glue-filled aquamarine.

Test and Analysis of the White Substance on the Surface of Gold Jewelry

SHEN Yunfeng, XU Yuewei, FAN Chengxing, WANG Weihua, ZHANG Zhi

2023, 25(1): 52-56. doi: 10.15964/j.cnki.027jgg.2023.01.007

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The silver-white spots of the gold jewelry were magnified and observed, and the causes of silver-white spot colour were analyzed by X-ray fluorescence spectra and metallographic analysis. The results show that there are obvious osmium (Os) and iridium (Ir) characteristic peaks by X-ray fluorescence spectroscopy, and two metallographic structures different from gold can be observed by metallographic microscope. The purpose of this paper is to improve the detection process of gold jewelry in laboratory, improve the ability of inspectors to identify and analyze characteristic peaks of elements, and provide a basis for rapid identification of this kind of jewelry and prevent it from entering the market through the detection of problematic samples. For gold adulterated products, the laboratory should not issue a certificate or label for the batch of products.

Research on the Design and Application of Cultural and Creative Product Design Based on Jingchu Culture IP——Taking the Design of the Character IP "Chu Tripod" and Its Derivative Products as An Example

JIN Ruoyu, ZHANG Ronghong

2023, 25(1): 57-65. doi: 10.15964/j.cnki.027jgg.2023.01.008

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The Jingchu Culture with a history of nearly 3000 years has provided rich material wealth and spiritual resources for the development of cultural and creative products in Hubei Province. However, the existing Jingchu Culture and creative product market has many problems such as a relatively single and conservative business model, serious homogeneity of product types, and lack of classic IP creation. And it is urgent for designers to integrate cultural relic resources, deeply explore the good Jingchu Culture resources, and actively carry out activation and utilization. As a cultural symbol with strong monetization and penetration ability and long monetization cycle, IP has the functions of strengthening identification, triggering emotional resonance, accurately targeting users, and multi-dimensional communication monetization for the development of cultural and creative products.By analyzing the feasibility of "Chu Tripod" as a prototype to build IP, this paper started from the aspects of visual symbol extraction and personalization setting, and determined the visual image and background story of the character IP "Lili", and carried out the design of online digital derivatives and offline physical derivatives from multiple dimensions, and discussed the design and application methods of IP-attributed cultural and creative products. Thus, this paper provided new ideas for fully exploring the convergence of Jingchu Culture and product design, finds new methods for designing with Jingchu Culture characteristics as the source of innovation, and used IP as a carrier to stimulate consumers' cultural identity and realize cultural inheritance to achieve the goal of cultural heritage and promotion.

The Aesthetic Expression of Chinese Image in Jewelry Art Design——Taking Dunhuang Fly Apsaras as An Example

REN Haiming

2023, 25(1): 66-71. doi: 10.15964/j.cnki.027jgg.2023.01.009

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Chinese image aesthetics boasts a long history, in which Chinese painting, calligraphy and poetry are especially time-honored. It strives to convey the implication beyond the finite description, which differentiates Chinese aesthetics from the western aesthetics. Thus, this characteristic of Chinese image aesthetics is the point that needs to pay attention to that would realize the art design that inherit and promote Chinese culture in the true sense. Therefore, taking Chinese image aesthetics as the theoretical basis, starting from the unique form, overall form, material and colour of jewelry art, this paper summarizes and puts forward universal design ideas based on the analysis of typical work cases: abstract in form shaping, white space in formal expression, material selection and elegant unity of oriental meaning, so as to arouse the viewer's aesthetic association with jewelry works, obtain aesthetic pleasure, and to explore a unique new path for the development of contemporary Chinese jewelry art. For practice, The author designed the jewelry Fly Apsaras Dancing with Dunhuang Fly Apsaras as the inspiration element, which shows the ethereal and flexible image beauty of the Fly Apsaras from the aspects of jewelry shape shaping, form expression, material selection and colour matching.

Study on the Efficiency and Quality of NC Carving of Jadeite——Take Sitting Maitreya Buddha Carving as An Example

MENG Yan, GENG Yukun, NA Xiuxi, CHEN Yufan

2023, 25(1): 72-80. doi: 10.15964/j.cnki.027jgg.2023.01.010

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CNC jade carving technology can reduce the labor cost of jade carving industry, improve production efficiency and upgrade the industry. Taking sitting Maitreya buddha as an example, in this paper, the authors use JDPaint5.50 to set different parameters to carve 13 pieces of jadeite with similar texture, and test the relationship between the processing quality, the degree of tool loss and the time-consuming by different tools. The results show that: when the speed is the same, the time consumption of using the flat head cutter for shaping is positively related to the depth, and the time consumption (s) is 142.27 ×depth (mm). When 0.6 mm tapered ball-end cutter is used in the rough jade cutter processing procedure, the maximum safe path space is 0.08 mm, and the percentage of speed is 25%. The time consumption of rough and fine cutting operations is related to the path space and the percentage of speed, and the extent of time consumption reduction decreases with the increase of path space and the percentage of speed. The surface quality of CNC jade carving is mainly related to the taper ball-end cutter head diameter and path space of the fine cutting process, and is independent of the percentage of speed. If the path space of rough cutting process is large, the machining allowance of rough cutting process should be increased to allow the fine cutting process to remove the trace of tool path.

Research on Features and Applications of Jadeite Jewelry and Product in Tengchong, China

Wang Wenwei, Lu Ren, Yin Zuowei

2023, 25(1): 81-88. doi: 10.15964/j.cnki.027jgg.2023.01.011

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Tengchong, an ancient border town located in southwest China, has more than 500 years of history in the trading and processing of jadeite. It is an important distribution center for jadeite and the birthplace of China's jadeite culture. Tengchong has three key advantages: location, culture and history, and is able to integrate local culture to form the unique style of "Yunnan Jade Carving". This article combines physical objects with related results of previous studies, based on the different usage and functions of jadeite jewelry and products in Tengchong, in order to analyze and summarize their classification and application. The four aspects of pattern, material, colour and technique are also been analyzed, as well as the linguistic features of jadeite jewelry and products in Tengchong, with the hope of providing ideas and references for the creation of modern jadeite jewelry.

Fashion with Abundant Gems and Pearls: Analysis of the Style of Jewelry in Jiajing and Wanli Periods of Ming Dynasty

HUANG Haodong

2023, 25(1): 89-100. doi: 10.15964/j.cnki.027jgg.2023.01.012

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In the Jiajing and Wanli periods of Ming Dynasty, the society has formed an atmosphere of comparison and luxury. Under the trend lead by the upper class at that time, the intensive inlaying of gems changed the style of jewelry in the middle and late Ming Dynasty, and the design style of jewelry inlaid with plenty of gems was gradually formed and emerged a new fashion. This paper analyzed the jewelry style at that periods from the perspectives of material, colour matching and pattern. It discussed the large-scale purchase and full set inlay of gems, analyzed the colour matching of the gems, the secular themes and the stylized composition in jewelry design at that period. Through this study, the author hopes to provide some new understandings and references for the jewelry style of Ming Dynasty.

Excavation and Application of Ideological and Political Education Elements in the "Systematic Gemmology of Jade" Course

YUE Suwei, CHEN Shimeng

2023, 25(1): 101-106. doi: 10.15964/j.cnki.027jgg.2023.01.013

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The excavation and application of ideological and political education elements in professional courses is the key of curriculum ideological and political construction. As the core course of gemmology and material technology, the course "Systematic Gemmology of Jade" plays a key role in cultivating professional knowledge and inspiring comprehensive literacy in gemmology. Carrying out ideological and political education in the course is of great significance to the promotion of students' professional quality and the formation of their values. This article sets out from the four aspects of the course, including jade formation, gemmological characteristics, jade identification and jade culture, and deeply excavates the outlook on life, values, scientific spirit, nationalism, and humanistic quality in each knowledge point, to achieve the goal of mutual integration and promotion of the ideological and political education elements and professional knowledge, and to achieve the goal of the cultivation of applied gemmological talents with excellent professional skills and character.

Practical Teaching Reform and Exploration of "Pattern" Course in Jewelry Design Major

WANG Wenwei, YIN Zuowei

2023, 25(1): 107-113. doi: 10.15964/j.cnki.027jgg.2023.01.014

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The course "pattern" is a basic course in jewelry design major and an important link between professional theories and core courses. From the perspective of application-oriented universities, this paper analyzes the current situation and problems of the "pattern" course during teaching. Concerning the derivative relationship between the "pattern" course and the curriculum group of the major, personnel training, practical application, assessment and evaluation, teaching and learning design and other aspects, this paper explores the development rules of the practical teaching reform of the "pattern" course in jewelry design major.

Practical Exploration and Teaching Reform of the Course "Fundamentals of Gemmology" for Non-Identification Jewelry Related Majors——Taking Wuhan University of Engineering Science as An Example

ZHANG Juan, QIN Dongmei, BAO Deqing, HUANG Xin

2023, 25(1): 114-119. doi: 10.15964/j.cnki.027jgg.2023.01.015

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"Fundamentals of Gemmology" course is one of the compulsory professional basic courses for jewelry majors, this paper starts from the analysis of the characteristics of the "Fundamentals of Gemmology" course, and in-depth analyzes the problems exist in the study of this course that the non-identification type jewelry major students meet. Through the reform of the curriculum syllabus, the teaching content is reorganized, the assessment methods are appropriately adjusted, and simple practical assessments are added to consolidate theoretical knowledge. On this basis, combined with the current advanced flipped classroom and PBL teaching methods, it fully stimulates students' desire to learn, relieves students' fear of difficulties, and makes students realize the importance of the course in the entire professional system. At the same time, dig deep into the ideological and political elements of the course, focus on the edification of aesthetics and art, and implement the fundamental task of morality and people. Combined with actual teaching experience, the path and method of curriculum reform were explored through teaching practice, and the effect of teaching reform was monitored, providing reference and basis for teaching reform of other similar professional courses.

Current Issue 2023, Volume 25, Issue 1

Current Issue
2023, Volume 25, Issue 1